TRS-80 was Tandy Corporation's desktop microcomputer model line, sold through Tandy's Radio Shack stores in the late 1970s and early 1980s.

In July 1980 Tandy released the TRS-80 Model III. The Model III could run about 80% of Model I software, but used an incompatible format for its 5-1/4" diskettes.

Improvements over the Model I included built-in lower case characters, an improved keyboard, 1500-baud cassette interface, and a faster (2.03 MHz) Z-80 processor.

Another significant change from the Model I was the self-enclosed style of the Model III--the monitor, keyboard, CPU and (optional) disk drives were all contained in one unit. This was a departure from the design of the Model I where the keyboard, monitor and disk drives were separate components.